When thinking about justified criminalization - whether some action may morally be made a criminal offense - philosophers tend to rely upon 'balancing'. Arguments favoring and opposing criminalization are 'weighed' on a simple beam balance; the 'weightier' reasons prevail. Jonathan Schonsheck argues that this methodology is deeply flawed; among other infirmities, it fosters the neglect of items essential to a defensible decision. He urges the adoption of 'filtering' - a multi-step procedure which directs one to discuss the moral authority of the state, to consider measures less coercive than a criminal statute, and to investigate the pragmatic consequences of criminalization. This procedure, he argues, imposes a structure on disputes which facilitates philosophical progress. 'Filtering' is then applied to an array of public policy issues, including laws which require the use of automobile seat belts and motorcycle helmets, and laws which prohibit the use of certain psychoactive substances ('drugs'). Additionally, the book addresses a number of more theoretical issues in the philosophy of the criminal law. Throughout, it engages the work of leading philosophers: Derek Parfit, Cass R. Sunstein, Richard J. Arneson, and especially Joel Feinberg.